package OfferCode;

import java.util.stream.IntStream;

/**
 * @Author Kechelle
 * @Date 2020/9/11 16:00
 * @Version 1.0
 */
public class Code64 {
    public static int sumNums(int n) {
        return IntStream.range(1,n+1).sum();
    }

    public static void main(String[] args) {
        System.out.println(Code64.sumNums(9));
    }
}
